Abstract

The Mooi River (Potchefstroom) is formed mainly by dolomite springs, one of which is on the farm Gerhardminnebron, 14 miles N.E. of Potchefstroom. The stones in the spring are covered with aquatic mosses while the central part of the spring, which has mainly a sandy bottom, has a growth of Nasturtium officinale R.Br. Watermites, mostly Thayasidae, were found chiefly amongst the roots of the water cress, and to a lesser extent in the moss.